~II~l4~JlOLLUTION

DYNEGY MIDWEST GENERATION, INC.,

(BALDWIN POWER STATION)

Respondent.

Dorothy Gunn, Clerk

Illinois Pollution Control Board

James R. Thompson Center, Suite 11-500

100 West Randolph Street

Chicago, IL 60601

CLERK’S

OFFICE

)

JUN202003

)

Brett J. Marshall

Water Programs Group Leader

Dynegy Midwest Generation, Inc.

2828 North Monroe Street

Decatur, Illinois 62526-3269

Please takenotice that I have today filed with the Office ofthe Clerk ofthe Illinois Pollution

Control Board

the

original

and

nine

(9)

copies

of the

PROVISIONAL

VARIANCE

RECOMMENDATION ofthe Illinois Environmental Protection Agency, a copy ofwhich

is served upon you.

ILLINOIS ENVIRONMENTAL PROTECTION AGENCY

By:

CL~X~J~

~

Deborah J. ~i1liams

Assistant Counsel

Division ofLegal

Counsel

Date:

June

18, 2003

Illinois Environmental Protection Agency

1021 North Grand Avenue East

P.O. Box 19276

Springfield, IL

62794-9276

217/782-5544

THIS FILING

IS SUBMITTED ON RECYCLED PAPER

\1

IUJ\~2UU\JLTl1L~i

Petitioner,

)

STATE OF ILUNOIS

)

Pollution

Control Board

)

)

PCB 03-

)

(Provisional Variance)

)

)

)

)

NOTICE

---

BEFORE THE ILLINOIS POLLUTION CONTROL BOARD

DYNEGY MIDWEST GENERATION, INC.,

)

(BALDWIN POWER STATION)

)

)

Petitioner,

)

)

v.

)

PCBO3-

)

(Provisional Variance)

ILLINOIS ENVIRONMENTAL

)

PROTECTION AGENCY,

)

)

Respondent.

)

ILLINOIS EPA RECOMMENDATION

The Illinois Environmental Protection Agency (“Illinois EPA”)recommends that the

requestedprovisional variance be granted subjectto the conditions set forth in paragraph ten

(10) below.

ACTION MUST BE TAKEN BY THE ILLINOIS POLLUTION CONTROL

BOARD

(“BOARD”)

WITHIN

2

DAYS

OF

NOTIFICATION

OF

THIS

RECOMMENDATION FROM THE ILLINOIS EPA.

1.

On June

12,

2003,

the Illinois

EPA received a

request for a provisional

variance from

Dynegy Midwest

Generation-Baldwin Power Station

(“Petitioner”).

The

provisional variance request letter is attached and incorporated as Exhibit A.

Petitioner is

requesting a provisional variance to allow temporary relief from the total suspended solids

(“TSS”) effluent concentration limits ofOutfall 001 during the dredging ofthe secondarycell

ofthe ash pond system.

2.

Petitioner

owns

and

operates a

coal-fired generating station

located

near

Baldwin, Illinois in St.

Clair and Randolph Counties.

The station is designed to provide a

maximum

generating

capacity of

1800

megawatts.

Petitioner

describes

the

ash

pond

---

wastewater treatment

system

as,

“The

ash pond

system

discharges

approximately

20.6

milliongallons ofwastewater(average flow)per day. Ofthis total, approximately 60 percent

consists offly ash sluice water and 40

percent bottom ash sluice water.

Each discharge is

routed to its separate ashdisposal cell before combining in the secondary pond.

The mixed

fly and bottom

ash waters then enter a final clarification (tertiary) pond prior to

entering a

channel, which discharges to the Kaskaskia River.”

Exhibit A at 2.

Petitioner is presently

required by

its National Pollutant

Discharge Elimination System

(“NPDES”) Permit No.

IL0000043 to

meet

TSS effluent

limits of

15

mg/l (monthly

average) and

30 mg/i

(daily

maximum).

3.

In describing the need forprovisional variance,Petitioner states, “Ijnitially

it

was believed that higher than average

flows through the ash pond were

causing the

TSS

exceedences.

It

wasn’t until

after

the

flows returned

to

normal

and

the

exceedences

continued, that it was discovered that only 1-2 feetofwater was available for settling, which

is

not

sufficient

for ash

clarification.”

Exhibit

A

at

1.

The Petitioner

further states,

“Baldwin

Power Station believes that immediate dredging ofthe secondary pond must be

initiated before flows through the ponds increase again, which would re-suspend evenmore

ash, resulting in higher TSS concentrations at the ash pond discharge.”

Exhibit A at 2.

4.

Petitioner addresses three alternative methods for compliance. The first two

alternatives ofstoring wastewateron-site and filtration are technicallynot feasible.

The third

alternative ofceasing plant operations would be

extremely burdensome.

The Illinois EPA

agrees with the Petitioner that no

other technically feasible

and

economically reasonable

alternative is known that can insure compliance with the NPDES permit while

repairs are

2

---

being completed.

5.

The Petitioner has indicated, and the Illinois EPA concurs, that denial ofthe

provisional variance request would impose an arbitrary and unreasonable hardship on the

Petitioner.

6.

The environmental impact on the receiving stream caused by this variance

request is expected to be

minimal.

7.

There areno federal lawsthat would preclude the granting ofthis provisional

variance.

8.

The

Illinois

EPA

believes

that no

public

water supply

will

be

adversely

affected by granting this provisional variance.

9.

The Petitioner has submitted no provisional variance requests to the Illinois

EPA in

calendar year

2003.

Baldwin

Power Station

was granted a

45-day provisional

variance for TSS effluent limitations from the ash pond system on September 2, 2002 (PCB

03-27).

10.

The Illinois EPA recommends that the Petitioner be grantedavariance from

35 Ill. Adm. Code

304.141(a) and the effluent limits in NPDES Permit No. 1L000004 as they

apply to total suspended solids for Outfall 001, subject to the following conditions:

a.

This variance shall begin June 16, 2003,

and continue for forty-five

(45)

days from that date or until completion ofthe project,

whichever occurs earlier.

b.

During the variance period, the

Petitioner shall meet

the monthly

average effluent concentration limits of50 mg/l for TSS.

c.

Petitioner shall complete the dredging and repair related work on the

3

---

secondary cell ofits ash pond system as expeditiously as possible.

During the provisional

variance period,the Petitioner shall operate the facility in such a mannerso as to produce the

best effluent possible.

d.

Petitioner shall continue to monitor and maintain compli-ance with all

other parameters and conditions specified in NPDES Permit No. IL0022403.

e.

Petitioner shallnotify Barb Conner ofthe Illinois EPAby telephone at

217/782-9720, when repairs on

the wastewater treatment

system are completed.

Written

confirmation shall be sent within five

(5)

days to the following address:

Illinois Environmental Protection Agency

Bureau of Water, Compliance Assurance Section

1021 North Grand Ave. East

P.O. Box

19276

Springfield, Illinois 62794-9276

Attn: Barb Conner

f.

Within ten (10) days of the date ofthe Board’s order,

the Petitioner

shall execute a Certificate ofAcceptance and agreement which shall be sent to Barb Conner

at the address indicated above.

ILLINOIS ENVIRONMENTAL PROTECTION AGENCY

By:

Date: June

18, 2003

1021 North Grand Ave. East

P.O. Box

19276

Springfield, Illinois 62794-9276

217/782-5544

Assistant Counsel

Division of Legal Counsel

4

---

Exhibit A

---

Dynegy Midwest Generation,

Inc.

~

1 ~

2003

2828 North Monroe Street

~.j

Decatur,

Illinois

62526-3269

June

12,2003

I

Mr.

Mike Garretson,

Manager

DYN EGY

Compliance Assurance Section

Division of Water Pollution control

Illinois Environmental

Protection Agency

P.O.

Box 19276

Springfield,

IL 62794-9276

Re:

Baldwin

Power Plant

NPDES Permit No.

110000043

Provisional Variance Request

Dear Mr. Garretson:

I.

Currently Applicable Regulations and Permit Requirements

In

accordance

with

Title

IX,

Section

35,

Subsection

(b)

of the

Illinois

Environmental

Protection

Act;

Part

180,

Chapter

2,

Subtitle

A,

Title

35

of the

IAC;

Procedures

and

Criteria for Reviewing Applications for Provisional Variances; and Title 40 of the Code of

Federal

Regulations,

Protection

of the

Environment,

Part

122.41

(n),

Dynegy Midwest

Generation

(DMG)

requests

that

a

provisional

variance

be

granted

from

the

daily

maximum and monthly average total

suspended solids (TSS) effluent limitations for the

ash

pond

discharge

(outfall

001)

at

Baldwin

Power

Station.

The

power

plant

is

authorized

to

discharge

wastewaters

under

the

authority

of

NPDES

Permit

No.

lL0000043, which was

issued on January 2,

1998.

The

purpose of

the

provisional

variance

is

to

provide

temporary

relief

from

the

TSS

effluent

limits

to

allow

-internal

maintenance-related

work

to

be

conducted

in

the

secondary

cell

of

Baldwin

Power

Station’s

ash

pond

system.

Over

the

past

several

months,

the

ash

pond

system

at Baldwin

Power Station

has

had

difficulty meeting

TSS

effluent limitations.

In an attempt to solve this problem,

a portion of the secondary pond

will

be dredged immediately and settling

capacity will

be restored.

Initially

it

was

believed

that

higher

than

average

flows

through

the

ash

pond

were

causing the

TSS exceedences.

It wasn’t until after the flows returned to

normal and the

exceedences continued, that it was discovered that only 1-2 feet of water was

available

for settling,

which

is

not

sufficient

for

ash

clarification.

Additional

TSS

samples were

collected

from the

bottom ash

field,

the fly

ash

field,

the

secondary

pond

(fly

ash

and

bottom

ash

combine

at

this

point),

and

the

tertiary

pond.

Through

this

sampling

program,

it was discovered

the effluent from

the fly

ash

pond and the effluent from

the

bottom

ash field

would

meet effluent

limitations if the compliance

sampling

points were

located

in

these

individual

cells.

However,

when

the

two

effluents

combine

in

the

---

Page Two

secondary pond

the TSS concentrations increase.

The reason for

the TSS

increase

is

because

flow

through

the

secondary

pond

is

re-suspending

previously

deposited

ash

and

carrying

it

into

the

tertiary

pond.

Baldwin

Power

Station

believes

that

immediate

dredging

of

the

secondary

pond

must

be

initiated

before

flows

through

the

ponds

increase

again,

which

would

re-suspend

even

more

ash,

resulting

in

higher

TSS

concentrations at the

ash pond discharge.

During the

period of the provisional

variance, DMG is

requesting that the current effluent

limitations for total

suspended solids of 15

mg/I for a 30-day monthly average

be raised

to

50

mg/I

and

the

daily

maximum

limit

be

eliminated.

The

provisional

variance

is

needed to allow dredging to be completed

in the southern-most portion of the secondary

pond.

Prior

experience

from

dredging

operations

has

shown

that

Baldwin

Power

Station

will

need

the

requested

provisional

variance

concentrations

to

ensure

compliance.

II.

Description of Business Activity

-

The

Baldwin

Power

Station

is

a

coal-fired

generating

station

located

near

Baldwin,

Illinois

in

St Clair

and

Randolph

counties.

Three generating

units

provide

a

maximum

capacity of 1680 megawatts.

Ill.

Current Wastewater Flows, Pollutant Loads, and Treated Effluent Quality

The

ash

pond

system

discharges

approximately

20.6

million

gallons

of

wastewater

(average flow) per day.

Of this total,

approximately 60 percent consists of fly ash

sluice

water and 40

percent bottom ash sluice water.

Each discharge

is routed to

its

separate

ash

disposal

cell

before

combining

in

the secondary pond.

The mixed

fly

and

bottom

ash

waters

then

enter

a

final

clarification

(tertiary)

pond

prior to

entering

a

channel

which discharges to the Kaskaskia River (Attachments

1).

IV.

Environmental

Impact Assessment

DMG

believes

that

the

impact

of

the

somewhat

elevated

TSS

concentrations

to

the

Kaskaskia

will

be

negligible

due

to

the

relatively

low

ratio

of

discharge

from

the

ash

pond

system

(31.9 cfs)

compared to current

river flows.

According to the

Illinois State

Water

Survey,

estimated

flows

at

the

Venedy

gauging

station

above

Baldwin

Power

Station’s river intake are

2130 cfs.

V.

Potential

Hardship

No immediate, readily-implementable

alternative for complying with the

ash

pond outfall

TSS

limitations

is

available,

other

than

ceasing

plant

operations.

Ceasing

plant

operations

would

impose

an

arbitrary

and

unreasonable

hardship

on

the

station

and

DMG.

The

purpose of the

dredging

is

to

immediately

restore

compliance

in

the

ash

pond

system

and

to

prevent

future

TSS

violations

from

occurring.

This

provisional

variance would

allow expedited

dredging

while

maintaining station

operation.

Baldwin

Power

Station

is

very

committed

to

returning

the

ash

pond

system

to

compliance

as

soon as possible.

---

Page Three

VI.

Proposal

According to the results of the

ash

pond depth

survey and the additional

TSS samples

that were

collected

in

the

individual

cells, the secondary pond

is the

probable source of

elevated

TSS.

This

proposed

maintenance-related

work activity

will

begin

during

the

third week of June and

is estimated to be completed around late July or early August.

VII.

Alternate

Methods of Maintaining Compliance with Permit Limits

During

Period of

Provisional Variance

DMG

has

considered,

and

rejected,

the

following

alternative

means

for

maintaining

compliance with

the

Plant’s

NPDES permit during this project:

A.

Ceasing Plant Operations

This

option

would

entail

shutting

down

the

plant

entirely,

which

obviously

cannot

be

-done due to

the

need

for generating electricity during the summer

months.

The cost to the company to shut down

the

plant would be

extremely

burdensome,

as

it

would

be

necessary

to

purchase

electricity

from

other

utilities.

B.

Storing Wastewater On-site

It is possible to store some ash sluice water for a number of days,

however,

it

is not possible to store wastewater for the entire projected time period.

C.

Filtration

The

plant

is

not

aware

of

any

portable

filtration

equipment

that

could

be

brought on-site to

handle

almost 20

MGD.

Smaller filtration equipment would

clog quickly and not

be able to handle the significant volume.

VIII.

Variance Period

A

provisional

variance

authorizing

the

release of

ash

pond

effluents

in

excess of

the

TSS limit is requested for June, 2003 and extending for 45 days.

IX.

Other Variances

Baldwin

Power Station was

granted

a 45-day Provisional Variance (PCB

03-27) for TSS

effluent

limitations

from

the

ash

pond

system.

This

provisional

variance

was

issued

September 2,

2002 and allowed dredging of the ash pond system to be performed.

---

Page Four

X.

Current NPDES Permit Status

The

existing

NPDES

permit

for

the

plant

was

issued

January

2,

1998

and

has

an

expiration

date

of January

31,

2003.

An

application

for

renewing the

NPDES

permit

was

submitted

on July 31, 2002 and a final

permit

is expected later this year.

XI.

Activities before the

Illinois Pollution Control Board

At

this

time,

DMG

has

no

other requests

before the

Pollution

Control

Board,

nor does

the

IPCB have any orders pending at this

plant.

XII.

Conclusion

Baldwin

Power

Station

is

committed

to

minimizing

any adverse

environmental

effects

during

the

provisional

variance

period

by efficiently

managing the

remaining

ash

pond

cells

still

in

operation.

DMG

believes

that

should

the

provisional

variance

not

be

granted,

the

result would

be

TSS

noncompliance

in

the

ash

pond

effluent

during

the

period

work,

which

is

occurring

in

the

secondary

pond.

The

Baldwin

Power

Station

believes

it

is critically important that the dredging

begin immediately to prevent ash from

carrying through

the

secondary cell and

accumulating

in

the tertiary cell,

elevating

TSS

concentrations

even

more.

Should

you

need

additional

information

regarding

this

provisional

variance

request,

please contact me at 217/876-3934.

Sincerely,

Brett J.

Marshall

Water Programs Group Leader

Attachment

---

II

II

II

ii

II

HI

-

~9SEC0N

P0

‘TERT

D~RY

ND

KA-SKASK IA

RIVER

FLY

ASH

____

BOTTOM

ASH

~

COMBINED

BOTTON

~.FLY

Baldwin

Power Plant Ash Pond System.

=

=

= =

=

~

=

~—.-

j

o

BOTTOM

ASF~-

DISCHARGE

TO

LEGEND

ASH

7

---

STATE OF ILLINOIS

)

COUNTY OF SANGAMON

)

)

PROOF OF SERVICE

I, the undersigned, on oath state that I have served the attached

PROVISIONAL

VARIANCE upon the persons to whom it is

directed, by placing a copy in an envelope

addressed to:

Ms. Dorothy M. Gunn, Clerk

Illinois Pollution Control Board

James R. Thompson Center

100 West Randolph St.

Suite 11-500

Chicago, Illinois 60601

(FAX

and

OVERNIGHT

MAIL)

Brett J. Marshall

Water Programs Group Leader

Dynegy Midwest Generation, Inc.

2828 North Monroe Street

-

Decatur, Illinois 62526-3269

(FIRST CLASS MAIL)

and mailing it from

Springfield, Illinois on June

18, 2003, with sufficient postage affixed

as indicated above.

SUBSCRIBED AND SWORN TO BEFORE ME

this f~ay

ofJune, 2003

Notary Public

-

-

-

.¶

-

OFFICIAL

SEAL

*

-

BRENDA BOEHNER

~: NOTARY

PUBLIC,

STATE

OF

ILUNOIS

*

5:MY

COMMISSION

EXPIRES

fl.14.2OO5:~

THIS FILING IS SUBMITTED ON RECYCLED PAPER